Add `any` predicate (#56)

source/index.ts

@@ -1,5 +1,6 @@
-import {ArgumentError} from './lib/argument-error';
-import {Predicate, validatorSymbol, Validator} from './lib/predicates/predicate';
+import {Predicate} from './lib/predicates/predicate';
+import {AnyPredicate} from './lib/predicates/any';
+import {testSymbol} from './lib/predicates/base-predicate';
 import {StringPredicate} from './lib/predicates/string';
 import {NumberPredicate} from './lib/predicates/number';
 import {BooleanPredicate} from './lib/predicates/boolean';
@@ -25,6 +26,20 @@ export interface Ow {
 	 * @param predicate Predicate used in the validator function.
 	 */
 	create<T>(predicate: Predicate<T>): (value: T) => void;
+	/**
+	 * Test that the value matches at least one of the given predicates.
+	 */
+	any<T1>(p1: Predicate<T1>): Predicate<T1>;
+	any<T1, T2>(p1: Predicate<T1>, p2: Predicate<T2>): Predicate<T1 | T2>;
+	any<T1, T2, T3>(p1: Predicate<T1>, p2: Predicate<T2>, p3: Predicate<T3>): Predicate<T1 | T2 | T3>;
+	any<T1, T2, T3, T4>(p1: Predicate<T1>, p2: Predicate<T2>, p3: Predicate<T3>, p4: Predicate<T4>): Predicate<T1 | T2 | T3 | T4>;
+	any<T1, T2, T3, T4, T5>(p1: Predicate<T1>, p2: Predicate<T2>, p3: Predicate<T3>, p4: Predicate<T4>, p5: Predicate<T5>): Predicate<T1 | T2 | T3 | T4 | T5>;
+	any<T1, T2, T3, T4, T5, T6>(p1: Predicate<T1>, p2: Predicate<T2>, p3: Predicate<T3>, p4: Predicate<T4>, p5: Predicate<T5>, p6: Predicate<T6>): Predicate<T1 | T2 | T3 | T4 | T5 | T6>;
+	any<T1, T2, T3, T4, T5, T6, T7>(p1: Predicate<T1>, p2: Predicate<T2>, p3: Predicate<T3>, p4: Predicate<T4>, p5: Predicate<T5>, p6: Predicate<T6>, p7: Predicate<T7>): Predicate<T1 | T2 | T3 | T4 | T5 | T6 | T7>;
+	any<T1, T2, T3, T4, T5, T6, T7, T8>(p1: Predicate<T1>, p2: Predicate<T2>, p3: Predicate<T3>, p4: Predicate<T4>, p5: Predicate<T5>, p6: Predicate<T6>, p7: Predicate<T7>, p8: Predicate<T8>): Predicate<T1 | T2 | T3 | T4 | T5 | T6 | T7 | T8>;
+	any<T1, T2, T3, T4, T5, T6, T7, T8, T9>(p1: Predicate<T1>, p2: Predicate<T2>, p3: Predicate<T3>, p4: Predicate<T4>, p5: Predicate<T5>, p6: Predicate<T6>, p7: Predicate<T7>, p8: Predicate<T8>, p9: Predicate<T9>): Predicate<T1 | T2 | T3 | T4 | T5 | T6 | T7 | T8 | T9>;
+	any<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(p1: Predicate<T1>, p2: Predicate<T2>, p3: Predicate<T3>, p4: Predicate<T4>, p5: Predicate<T5>, p6: Predicate<T6>, p7: Predicate<T7>, p8: Predicate<T8>, p9: Predicate<T9>, p10: Predicate<T10>): Predicate<T1 | T2 | T3 | T4 | T5 | T6 | T7 | T8 | T9 | T10>;
+	any(...predicate: Predicate[]): Predicate;
 	/**
 	 * Test the value to be a string.
 	 */
@@ -159,23 +174,15 @@ export interface Ow {
 	readonly iterable: Predicate<Iterable<any>>;
 }
 
-const main = <T>(value: T, predicate: Predicate<T>) => {
-	const validators: Validator<any>[] = (predicate as any)[validatorSymbol];
-
-	for (const {validator, message} of validators) {
-		const result = validator(value);
-
-		if (typeof result !== 'boolean' || !result) {
-			// TODO: Modify the stack output to show the original `ow()` call instead of this `throw` statement
-			throw new ArgumentError(message(value, result), main);
-		}
-	}
-};
+const main = <T>(value: T, predicate: Predicate<T> | AnyPredicate<T>) => (predicate as any)[testSymbol](value, main);
 
 Object.defineProperties(main, {
 	create: {
 		value: <T>(predicate: Predicate<T>) => (value: T) => main(value, predicate)
 	},
+	any: {
+		value: (...predicates: Predicate[]) => new AnyPredicate(predicates)
+	},
 	string: {
 		get: () => new StringPredicate()
 	},

source/lib/predicates/any.ts

@@ -0,0 +1,31 @@
+import {ArgumentError} from '../argument-error';
+import {Predicate} from './predicate';
+import {BasePredicate, testSymbol} from './base-predicate';
+import {Ow} from '../..';
+
+/**
+ * @hidden
+ */
+export class AnyPredicate<T> implements BasePredicate<T> {
+	constructor(
+		private readonly predicates: Predicate[]
+	) {}
+
+	[testSymbol](value: T, main: Ow) {
+		const errors = [
+			'Any predicate failed with the following errors:'
+		];
+
+		for (const predicate of this.predicates) {
+			try {
+				main(value, predicate);
+
+				return;
+			} catch (err) {
+				errors.push(`- ${err.message}`);
+			}
+		}
+
+		throw new ArgumentError(errors.join('\n'), main);
+	}
+}

source/lib/predicates/base-predicate.ts

@@ -0,0 +1,13 @@
+import {Ow} from '../..';
+
+/**
+ * @hidden
+ */
+export const testSymbol = Symbol('test');
+
+/**
+ * @hidden
+ */
+export interface BasePredicate<T = any> {
+	[testSymbol](value: T, main: Ow): void;
+}

source/lib/predicates/predicate.ts

@@ -1,4 +1,7 @@
 import is from '@sindresorhus/is';
+import {Ow} from '../..';
+import {ArgumentError} from '../argument-error';
+import {BasePredicate, testSymbol} from './base-predicate';
 import {not} from '../operators/not';
 
 /**
@@ -24,7 +27,7 @@ export const validatorSymbol = Symbol('validators');
 /**
  * @hidden
  */
-export class Predicate<T = any> {
+export class Predicate<T = any> implements BasePredicate<T> {
 	constructor(
 		type: string,
 		private readonly context: Context = {
@@ -37,6 +40,20 @@ export class Predicate<T = any> {
 		});
 	}
 
+	/**
+	 * @hidden
+	 */
+	[testSymbol](value: T, main: Ow) {
+		for (const {validator, message} of this.context.validators) {
+			const result = validator(value);
+
+			if (typeof result !== 'boolean' || !result) {
+				// TODO: Modify the stack output to show the original `ow()` call instead of this `throw` statement
+				throw new ArgumentError(message(value, result), main);
+			}
+		}
+	}
+
 	/**
 	 * @hidden
 	 */

source/test/any.ts

@@ -0,0 +1,21 @@
+import test from 'ava';
+import m from '..';
+
+const createError = (...errors: string[]) => {
+	return [
+		'Any predicate failed with the following errors:',
+		...errors.map(error => `- ${error}`)
+	].join('\n');
+}
+
+test('any', t => {
+	t.notThrows(() => m(1, m.any(m.number)));
+	t.notThrows(() => m(1, m.any(m.number, m.string)));
+	t.notThrows(() => m(1, m.any(m.number, m.string)));
+	t.notThrows(() => m(true, m.any(m.number, m.string, m.boolean)));
+	t.throws(() => m(1 as any, m.any(m.string)), createError('Expected argument to be of type `string` but received type `number`'));
+	t.throws(() => m(true as any, m.any(m.number, m.string)), createError(
+		'Expected argument to be of type `number` but received type `boolean`',
+		'Expected argument to be of type `string` but received type `boolean`'
+	));
+});